There's a difference between needing to lock down the whole OS and just the secure element. The secure hardware component can sign a challenge and prove possession of a private key without you being able to extract it. Smartcards have done this for decades (most people here will know an implementation under the name Yubikey).

Conveying authentic information across untrusted channels (your phone screen, say) has been a solved problem since asymmetric cryptography was invented back before I was born

If your app needs to be protected from harm, it cannot protect the user from said harm. I hoped software engineering culture was lucky to not have the same precepts that make lockpicking a crime in the real world, that we successfully make it into common knowledge that you can't grant any trust to the client, but it seems "trusted computing" is making some of us unlearn that lesson.

> an adversarial environment that actively tries to break the app's integrity

Can you elaborate on what this means? Who is the adversary? What kind of 'integrity'? This sounds like the kind of vague language DRM uses to try to obscure the fact that it sees the users as the enemy. An XBox is 'compromised' when it obeys its owner, not Microsoft.

Users have the right to modify any app running on their own device. Software security should never depend on the user having no control over their own device. Smartphones are essentially just regular computers, and on them you can use a debugger and do whatever you want. Viewing smartphones as closed systems like game consoles where you need the manufacturer’s permission for everything only leads us into the dystopia that Richard Stallman described as early as 1997 in his short story "The Right to Read"

Comparing being able to run the hardware and software of your choice to "wanting a passport in a different color or whatever" is so completely fucked, and it's beyond insane as a justification for giving two American tech companies with a well established track record for doing evil control over your citizens' ID.

The world has gone absolutely mad, what the fuck am I even witnessing? It is quite literally becoming 1984 in front of my eyes, with people complying completely voluntarily and openly advocating for it, not even a threat of force to make it happen.

Well, in that case, if they want full control and attestation yadda yadda, I'm fine with them shipping me a device they fully control exclusively for use of this stuff. But if we're talking about my smartphone that I paid for with my money that I worked for, I will do whatever I damn please with it. So I guess that means eIDAS will be inaccessible to me.

True, but its really hard to name a family of commercial devices with security features in hardware, including serious security features, which were not eventually hacked.

Worse still, for new mainstream devices that are believed to be safe the state sponsored actors will likely operate unpublished exploits, and will exploit the misplaced faith people and judiciary will put in device attestation. I dont think the very likeable people who worked on Pegasus found themselves respectable jobs - they are likely still selling that sophisticated crap to all authoritarian regimes.